The present invention relates generally to a epitrochoidal rotary device and, more particularly, to an outer envelope epitrochoidal air compressor.
Rotary epitrochoidal devices are known generally in a variety of forms. Some function as prime movers while others are driven by prime movers to, for example, compress air. All have in common a rotor moving in a chamber rather than a reciprocating piston. For example, the Wankel et al. U.S. Pat. No. 2,988,065 discloses a rotary internal combustion engine in which a rotor moves within a lobed chamber in a housing while the rotor and housing both rotate.
West German Patent No. 25 18 737 by Lambrecht discloses a single-ended crankshaft in a rotary device. The crankshaft rotates and carries an off-balance fly wheel. A single-ended crankshaft is also disclosed in Doyer U.S. Pat. No. 3,285,189 in a motor, pump, or compressor with a piston rotatable within a housing. The crankshaft in Doyer also rotates and carries a counterweight.
The above-identified Lambrecht German patent also discloses a pinion gear and rotor in a rotary device which are keyed or connected together. A key connected rotor and pinion gear are also shown in Glenday et al. U.S. Pat. No. 3,384,055.
Lateral seals for rotors in rotary devices are known in a variety of forms. For example, Sabet U.S. Pat. No. 3,357,412 and Arai U.S. Pat. No. 4,243,233 each show split ring seals in rotary devices. Buttons holding seals in the lateral faces of a rotor are shown in Hart U.S. Pat. No. 3,930,767. A circularly moveable strip on the face of a rotor is shown in Peras U.S. Pat. No. 3,185,386.
Various lubricating systems are also known in the art for rotary devices. For example, Peras U.S. Pat. No. 3,343,526 discloses a lubrication channel in a shaft of a rotary engine. A rotor bearing lubrication system is disclosed in Corwin U.S. Pat. No. 4,477,240 for use in a rotary internal combustion engine and having a channel in an eccentric portion of a main shaft.
In the Deane U.S. Pat. No. 3,825,375 is disclosed an inner envelope epitrochoidal external combustion engine driven by high pressure gas. A valve is formed by a valve seat, bias spring and ball for sealing starter ports that lead from a gas inlet to the rotor chamber. Centrifugal force causes the ball to close off the starter port.
In Paschke U.S. Pat. No. 3,012,550 is disclosed a rotary device in which a rotatable outer body is provided with cooling fins.
In many known rotary devices, rotor wobble is a problem. For example, in Wankel engines, the ring gear is mounted flush with the face of the rotor and is part of the rotor. The gear teeth are typically involute and the rotor is mounted with a single bearing on one side of the gear. Both tangential and radial force components are possible with the involute gear teeth so that the radial components cause the rotor to tip about the bearing as it revolves. Although various means are used to counteract this tipping, some wobble still occurs. The seals are unable to react fast enough to provide a good seal so that oil passes the seal grid and contact and compression is lost.